A recent article in the New York Times praised the partnership between public libraries and e-books.

“But some publishers worry that the convenience of borrowing books electronically could ultimately cut into sales of print editions.

“I don’t have to get in my car, go to the library, look at the book, check it out,” said John Sargent, chief executive of Macmillan, which publishes authors like Janet Evanovich, Augusten Burroughs and Jeffrey Eugenides. “Instead, I’m sitting in the comfort of my living room and can say, ‘Oh, that looks interesting’ and download it.”

As digital collections grow, Mr. Sargent said he feared a world in which “pretty soon you’re not paying for anything.” Partly because of such concerns, Macmillan does not allow its e-books to be offered in public libraries.

Simon & Schuster, whose authors include Stephen King and Bob Woodward, has also refrained from distributing its e-books to public libraries. “We have not found a business model that works for us and our authors,” said Adam Rothberg, a spokesman.

For now, the advent of e-book borrowing has not threatened physical libraries by siphoning away visitors because the recession has driven so many new users seeking free resources through library doors. And in some cases, few library patrons seem to know that e-book collections even exist.”